Nonwoven fabrics are defined as plane sheet- or web-shaped fabric structures mechanically or physically bonded together by entangling fiber, such as natural fiber, chemical fiber, glass fiber, metal fiber, etc., according to the characteristics of the fiber.
Recently, nonwoven fabrics are widely used in various industrial and home applications and their uses and properties have been increasingly known to the actual demanders, leading to creation of their more different applications.
With many expanded studies made on the applied science as in many developed countries, multifunctional nonwoven fabrics according to high edge technology have recently been progressively introduced and developed in rapid progress.
The nonwoven fabrics applied in the medical field are used as surgical drapes, pads, dressings, filters, or tissue scaffolds implanted for regeneration of internal organs of the body, in addition to surgical gowns, masks, and so forth.
FIG. 1 illustrates the process of preparing a wet-laid nonwoven fabric using the paper making process that involve (1) beating the fibers; (2) dispersion of the fibers in an aqueous medium, which is carried out repeatedly when necessary; (3) web formation on the paper-making wire or screen mesh 31 as a result of filtration and pressing it in the form of a sheet with a vacuum pump 32; (4) passing the web through press rollers to form a wet-laid nonwoven fabric; and (5) winding the wet-laid nonwoven fabric. The sheet thus obtained is made of short-cut fibers, for example, 1 to 7 mm long in water in order to get uniform dispersion of fiber, leading to better uniformity than dry-laid nonwovens.
In an attempt to use wet-laid nonwoven fabrics prepared by the paper making process for medical applications, the inventors of the present invention have found it out that the optimal conditions to improve the strength of nonwoven fabric allows preparation of a medical nonwoven fabric comprising gelable cellulose derivative short-cut fibers and facilitates the control of the gelation time through capillary actions caused by the micropores between the gelable cellulose derivative short-cut fibers, so they have contrived a nonwoven fabric suitable for medical use and further developed a composite nonwoven fabric or a dyed nonwoven fabric with improved dimensional stability and visibility during the surgical procedure using the single-component nonwoven fabric of the present invention, which is also applicable as an adhesion prevention barrier, thereby completing the present invention.